Thank you for your comment: I was aware that my iPhone could estimate location without having phone call capability but had mistakenly assumed some degraded ability to triangulate off of distant cell towers. Your flat declaration of GPS capability caused me to do a little research and indeed you are right. However, Garmin devices are superior in a North American context because of the ability to also use better information available about variations in atmospheric density affecting sat signals. It appears the iPhone would be superior in a European context where the ability to use a different source of such atmospheric information comes into play in a way the Garmin device isn't built to use. My experience is mostly in Canada.
Now that I did now know. However what you say should apply equally to OS Maps and ViewRanger, there should be no difference in accuracy between the two, it is the Phone that provides the data.
(With regards to triangulation, the phone and the network can triangule your position from the towers with a degree of accuracy, but nothing like as good as with GPS, and with no height component)
Protanope wrote:I don't usually use power saving features set on my phone because recharging either in the car or in any building is typically available with no less than 12 hours delay. The way I use my phone, that works for me.
I was referring to the power saving features in the ViewRanger App. the iPhone version has some very specific settings relating to trading off accuracy against battery life. On my version they're under Settings->GPS. GPS mode needs to be set to continuous and GPS Single Fix should be Off, if you want the best accuracy. But be prepared to run out of battery very fast. Or do what I did and use the otherwise useless old Samsung Android phone I had lying in a drawer and run Viewranger on that instead, going all day on one battery. Samsung Galaxy XCover phone is waterproof and available cheap on eBay....
Protanope wrote:With respect to 1:25000 OS Maps: I get a different level of ability to zoom in on those maps depending on whether I access them on my desktop machine so the limit is 100 ft on the map being about 7/8 inch on my screen. If I try to access the same OS Map using the OS Maps App on my iPhone I am severely limited in the degree to which I can zoom in the 1:25000 maps to the point that the twists and turns in some paths are not fully and correctly represented consistent with what I can see accessing the same map on my iMax. So the question is, if I accessed that same map through a purchased map tile on ViewRanger, would my ability to zoom in to see all the details be impaired similarly to how it is impaired in Ordinance Survey's own iPhone Map App?
Thank you for your consideration.
May I suggest you just try purchasing a tile and see if it suits you? It's not exactly expensive. Trying to visualize what you're describing there is making my head hurt.